In recent years, digital still cameras and mobile terminals incorporating a camera which include a positioning unit utilizing a satellite positioning system (a global navigation satellite system (GLASS), for example) have been widely used. Such a device is capable of recording information on a photographing position associated with image data obtained by photographing. Furthermore, various personal computer applications utilizing image data associated with positional information obtained in this way have become popular. For example, PTL 1 discloses a technique of distinguishing image data having positional information recorded in attribute information of the image data from image data which does not have positional information to be recorded by displaying icons representing that the positional information is recorded in attribute information of image data to be displayed. However, although a result of a determination as to whether positional information is recorded in image data may be obtained in the method in the related art, accuracy of the positional information is not examined.
In general, a plurality of types of positioning methods of positional information have been used. For example, in a case of a digital still camera including a receiver which receives electric waves supplied from the satellite positioning system, under a condition in which the digital still camera may receive a signal from a satellite, positional information obtained by the signal is recorded as attribute information of image data. Furthermore, in a case of a digital still camera or a mobile terminal which includes a wireless LAN, positional information obtained from a nearest wireless base station may be recorded in image data. As another method, arbitrary positional information may be manually recorded using an operation unit in image data which does not include positional information recorded therein. In this case, wrong positional information may be input due to the manual operation.
Furthermore, when the satellite positioning system is used, since electric waves supplied from satellites are used, accuracy of positional information varies depending on an environment of the receiver and types, arrangement, the number of satellites, and the like.
As described above, a plurality of positional information may exist in terms of accuracy or reliability, and to examine the positional information, it is insufficient that presence and absence of positional information is simply determined.